This paper introduces the shining medical ethics of modern medical specialists who commit themselves on medical career with no fear of squalidity,contamination,and with no complaining with vivid examples,providing concrete role models for medical staff.

Objective To investigate quercetin's protective effect against oxidative stress in and impact on the biological activity of mouse B10BR melanocytes. Methods B10BR cells were cultured and treated with different concentrations of quercetin followed by additional culture. Then, cell viability was measured by using MTT assay, hydrogen peroxide-induced cell apoptosis by flow cytometry, and cell morphological changes by microscopy. The tyrosinase activity in and melanin synthesis by B10BR cells were measured by dopa oxidation assay and sodium hydroxide (NaOH)-lysis method, respectively. Results After treatment with quercetin of 33.33 μmol/L for 24 hours, the survival rate of B10BR cells reached (94.22 ± 3.36)%, tyrosinase activity (107.15 ± 10.96)%, and melanin content (111.85 ± 9.49)%. A significant difference was observed in tyrosinase activity and melanin content between hydrogen peroxide-induced and 33.33 μmol/L quercetin-treated B10BR cells and those only induced by hydrogen peroxide (both P < 0.01). Flow cytometry revealed that quercetin inhibited hydrogen peroxide-induced apoptosis in melanocytes. Conclusion The protective effect of quercetin against hydrogen peroxide-induced apoptosis in melanocytes may provide a new idea for the treatment of vitiligo.

Objective To evaluate the feasibility and significance of CT image-based threedimensional (3D) brachytherapy for cervical cancer.Methods Three-dimensional (3D) plan and twodimensional (2D) plan were designed for 55 CT images of brachytherapy from 12 cervical cancer patients who received radical radiotherapy in 2013.Dosimetric comparison was performed between the 3D plan and 2D plan,and paired t-test,Wilcoxon signed rank test,Pearson correlation analysis,and Spearman correlation analysis were performed.Results A point dose,D90,V100,CI,and CI' in 3D plan were higher than those in 2D plan (P=0.015,0.016,0.000,0.000,0.000).Bladder point dose,rectal point dose,and rectal D2 cm3 in 3D plan were slightly higher than those in 2D plan,but hot spot dose was significantly reduced in 3D plan (P =0.140,0.123,0.214).Bladder D2cm3 was significantly higher than bladder point dose (P =0.000).Sigmoid colon D2cm3 was more correlated with the average doses of the three highest rectal points than rectal D2 cm3 (r =0.314,0.630,P =0.000,0.000).V100 showed a linear relationship with high-risk CTV (r =0.981,P =0.000).Bladder D2cm3 was higher than 430 cGy when the bladder volume was more than 80 cm3 ;small intestinal D2 cm3 did not change significantly when the bladder volume was less than 115 cm3,but decreased significantly once the volume exceeded the value.Conclusions Compared with the traditional 2D plan,the 3D plan for CT image-based cervical cancer brachytherapy significantly increases the target coverage and conformity index,but does not significantly increase the doses to organs at risk.Point dose evaluation is confirmed to be inaccurate.The doses to the bladder,rectum,and small intestine can be adjusted by controlling the bladder volume.

Objective:To explore the application and effect of team-based learning (TBL) combined with flipped classroom in the teaching of physiology.Methods:A total of 70 medical students were selected and randomly divided into two groups, experimental group ( n=34) and control group ( n=36). Both groups studied digestion physiology by different method. In the experimental group, the students were taught by TBL combined with flipped classroom. The control group was given traditional teaching. The students studied and discussed problems in a team, and shared the answers in the flipped classroom. The effects of teaching were evaluated by the final test scores and the self-made questionnaire. SPSS 17.0 was used for t test on data comparison between the two groups. Results:The test scores of digestion physiology in the experimental group were (5.47±1.02) points, which were significantly higher than those of the control group (4.42±1.63) points, with significant differences ( P=0.020). A total of 34 questionnaires were issued and 34 valid questionnaires were collected, with an effective rate of 100%. The questionnaire results showed that TBL combined with flipped classroom was accepted and approved by about 82% of students in the experimental group who agreed that the teaching model helps enhance students' initiative and interest in learning, develop their sense of cooperation and comprehensive application ability. Conclusion:TBL combined with flipped classroom is feasible and effective in the physiological teaching, and it can be popularized in medical courses.

Objective To study the dosimetric comparison of split field and fixed jaw techniques for large IMRT target volumes in the rectum cancer.Methods CT images of fifteen patients with rectum malignancies and regional target volumes were transferred into Eclipse planning system.SFT plan and FJT plan were performed on an Eclipse TPS using beam data generated for linear accelerator.A standard beam arrangement consisting of seven coplanar fields was used in both techniques.Institutional dose-volume constraints used in rectum cancer were kept the same for both techniques.Target and organs at risk were evaluated.Results PTV95 in FJT plan coverage was lower (t =-2.24,P ＜ 0.05).Dmean in FJT plan was increased (t =2.54,P ＜ 0.05),but Dmax was not different.HI in FJT plan became inferior (t =3.09,P ＜0.05),while CI was not different.There was no difference in dose distribution among bladder,femoral head and cauda equina.The value of V5 of small intestine increased in FJT plan (t =4.76,P ＜0.05),and the values of V20 and V50 of bone marrow were better than those in SFT plan (t =-2.66,-3.36,P＜0.05),while Dmax was higher than that in SFT plan (t =3.30,P ＜ 0.05).The value of V20 of body was higher in FJT plan than that in SFT plan (t =2.48,P ＜0.05).The number of MU was significantly lower in FJT plan than that in SFT plan (t =-9.38,P ＜0.05).The average segments in FJT plan decreased by 39.4％ compared with SFT plan (t =-6.46,P ＜ 0.05).Verification rate in FJT plan group was better than that in SFT plan (t =10.46,P＜0.05),and the treatment time was shortened from 12 to 6 min.Conclusions Compared to SFT technique,patients with rectal cancer who were treated with FJT could get better dose of target and organs,which can meet the clinical treatment requirements.The technique could shorten the treatment time and reduce the treatment MU.It also could increase the number of patients to be treated,reduce their waiting time and reduce the difficulty of QA.

Objective To investigate bladder anatomical changes and dose variation in patients with cervical cancer.Methods We analyzed 20 patients,undergoing external beam radiotherapy scanning cone beam CT(CBCT)before each fraction.Bladder was contoured on each CBCT,was projected onto the planning CT and assesses anatomical changes and dose variation.Results A total 451 CBCT images,for 20 patients were collected for analysis,show more change in bladder volume and position.In 15 cases bladder volume and V45 had no significant correlation(r=0.225 -0.473,all P>0.05),4 cases shows negative correlation(r=-0.564,P<0.05;r=-0.597,P<0.01;r=-0.942,P<0.01;r=-0.816,P<0.01),1 case shows positive correlation(r=0.662,P<0.01).Have more than the criteria(V45≤50%)number is 64/451(14.2%)in whole treatment.Conclusions For most patients by filling adequacy bladder,bladder dose variation is acceptable:CTV lager for individual patients should be closely observed its regression,implementation of the offline or online calibration.

Objective To compare the dosimetry characteristics of volumetric intensity-modulated arc therapy (VIMAT) and fixed field intensity-modulated radiation therapy (FF-IMRT) for cervix cancer.Methods CT images of 13 patients with cervix uteri cancer were transferred into Eclipse planning system.FF-IMRT and VIMAT plans were optimized on an Eclipse treatment planning system using beam data generated for Varian trilogy linear accelerator.Planning target volume (PTV) and organs at risk were evaluated with dose-volume histogram.To appraise the difference between the techniques,the paired t-test was applied.Results Compared with the FF-IMRT plans,PTV95％ coverage of VIMAT plan group increased (t =9.84,P =0.000),PTV110％ became lower (t =-3.72,P =0.003),Dmax decreased (t =-3.51,P=0.005),and CI became worser (t=5.39,P=0.000).PTV105％,Dmean,and HI had no difference (t =-0.02,-0.60,1.13,P =0.842,0.560,0.283).V30 of the bladder was reduced by about 10％ (t =-4.99,P =0.000),and Dmean and Dmax were 1.4 Gy and 1.5 Gy lower respectively (t =-3.65,-18.03,P =0.004,0.000) ;V40 of the rectum was reduced by about 10％ (t =-2.99,P =0.012),and Dmean and Dmax were reduced by 0.6 Gy,0.8 Gy respectively (t =-2.98,-4.05,P =0.013,0.002) ;V30,V40 and V50 of the small intestine were reduced by 16％,10％ and 11％ (t =-10.85,-4.74,-8.66,P =0.000,0.001,0.000),and Dmax was reduced by 0.8 Gy (t =-9.45,P =0.000) ; V30,V40 and V50 of the bone marrow were reduced by 26％,19％ and 16％ (t =-22.10,-10.19,-4.04,P =0.000,0.000,0.002),and Dmean reduced by 1.9 Gy (t =-16.21,P =0.000) ; D5 of the left and right femoral heads were reduced by 1.6 Gy and 2.7 Gy (t =-2.89,-6.22,P =0.015,0.000).Dmax of the caudate equine was reduced by 1.5 Gy (t=-4.80,P=0.001).V20,V30,V40 and V50 of the body were reduced by 18％,18％,4％ and3％(t=-7.52,-11.75,-6.26,-6.94,P=0.000,0.000,0.000,0.000).Dmean and Dmax of the body decreased by 1.0 Gy and 0.4 Gy (t=-3.72,-3.51,P=0.000,0.005).Average machine unit (MU) decreased by 57％ (t =-40.54,P =0.000).Conclusions cervical cancer Patients with VIMAT technology can get equivalent or superior dose distribution compared with the FF-IMRT technology.And VIMAT technology could reduce MU.But the efficacy needs further clinical evaluation

Objective To analyze the outcomes of radiotherapy for keloids by high energy electron beams and the factors influencing the treatment outcome.Methods From Jan 1998 to Jun 2012,846lesions in 578 patients received radiotherapy.The median age is 29 years old (range 5-80 years old).There are 841 lesions with postoperative radiotherapy and 39 lesions with skin-grafting.656 lesions treated within 1 day after operations.The max diameter of 348 keloids are ＞ 5 cm.We used 6 MeV and 7 MeV electron-beam radiation therapy.The total dose ranging from 16-18 Gy/2f (interval 1 week).Treatment fields including entire keloid scars,and any suture/puncture holes with a 1 cm-margin around the lesion were used.The skin grafting patients need radiotherapy after the flap survived (about 10-15 days after the operation).The median follow-up period was 36 months (range 8-185 months).Results There are 736 (87.0％) of 846 lesions with radiotherapy effective.Other 89 (10.5％) lesions relapse in 4-33 months (median 12 months).21 lesions were of no avail.The univarate analysis shows that keloids length,keloids location,skin-grafting,interval between operations and irradiations are the influencing factors of outcomes (P =0.007,0.000,0.000,0.001).The multivariate analysis shows that keloids location and skin-grafting remained statistically significant differences (P =0.001,0.001).Most of the recurrence cases are large and bent scars.Conclusions High-energy electron-beam radiotherapy for keloids can receive good outcomes.Treatment fields flat is very important for electron-beam radiotherapy.

Objective To investigate the safety and efficacy on early treatment of large pancreatic pseudocyst by endoscopic ultrasound (EUS)-guided transgastric drainage. Methods The clinical data of 23 cases of large pancreatic pseudocyst treated with EUS-guided transgastric drainage from 2003 to 2008 was retrospectively analyzed. Results All were of single pseudocyst. Pseudocyst was present in the head of the pancreas in 3 cases, in the body of the pancreas in 11 cases, in the tail of the pancreas in 9 cases. Mean diameter of pancreatic pseudocysts was 11 cm( range 8 - 18 cm ). The interval between the finding of pseudocysts and EUS-guided transgastric drainage ranged 17 -65 d, averaging 31 d. Two had postoperative infection of the pseudocyst, one received percutaneons external drainage and the other one received surgical internal drainage. Three had postoperative gastrointestinal bleeding and were treated with antacid and hemostatic drugs. Patients were examined by CT two to three months later. Pancreatic pseudocysts disappeared completely in 6 cases and significantly shrank in the rest. The clinical symptoms of all patients,such as abdominal pain, abdominal bloating were significantly relieved. All patients were followed-up for 1 year, there was no pseudocyst recurrence, ulcer,bleeding or infection. Conclusions Early treatment of large pancreatic pseudocyst by EUS-guided transgastric drainage is safe and effective.

Objective To analyze the efficacy,late complications and prognostic factors of post-op-erative radiotherapy for cervical cancer. Methods From Nov. 1999 to Feb. 2005,114 patients with cervi-cal cancer received adjuvant pelvic radiotherapy after radical hysterectomy and pelvic lymphadenectomy. The median age was 42.5 (24 to 72) years old. According to the FIGO staging system,6,51,18,26 and 13 pa-tients had stage ⅠA, Ⅰb1, Ⅰb2, ⅡA and ⅡBdisease. The pathological type was squamous cell carcinoma,ade-nocarcinoma, squamous-adenocarcinoma and undifferentiated carcinoma in 92,19,2 and 1 patients, respec-tively. The whole-pelvic external beam irradiation of 50 Gy (40 to 60 Gy) was given with 6 MV or 15 MV X-ray beams using four-field box technique. Eighty-one patients received intravaginal brachytherapy of 16 Gy (4 -30 Gy in 1 -6 fractions) 4 weeks after the beginning of radiotherapy, with the referrence point being at 0.5 cm under the vaginal mucosa. Eighty-seven patients received preoperative and/or concurrent chemother-apy. The survival and independent prognostic factors were analyzed by Log-rank method and Cox model. Results The median follow-up time was 26.0 (5 - 75) months. The overall survival rate, disease-free sur-rival rate and local control rate were 93.1%, 88.1% and 94.6% at 2-year, and 75.7%, 62.3% and 85.6% at 5-year,respectively. The independent prognostic factors were lymph node metastasis and positive surgical margin for overall survival, positive surgical margin for local control, and stage, uterine body invasion and positive surgical margin for disease-free survival. Sixteen patients ( 14% ) had distant metastasis, and the most common sites were the lung,inguinal region,bone,liver and brain. According to RTOG grading sys-tem, the incidence of late gastrointestinal side effects of grade 1,2 and 3 was 11.4%, 11.4% and 3.5%. The corresponding genitourinary side effects were 14.0% ,6.1% and 0.9%, respectively. The incidence of leg lymphedema was 7 % . Conclusions Post - operative radiotherapy can achieve good local control in cervical cancer with acceptable late side effects. Distant metastasis is the main cause of death.